Fig. 7. Stimulation of tyrosinase activity of B16 cells by 8a–8o. N means negative control; P means positive control (8-MOP). B16 cells was treated with 50 μM different furocoumarin derivatives for 48 h. After that, tyrosinase activity was measured directly. The data are the mean ± SD of three experiments, P < 0.05.
